Ground-working implements of a tractor-drawn type can include a cutting tool and a smoothing board which cooperates therewith in leveling the turned ground, upon a common tractor-drawn or tractor-mounted support. Such implements generally have a common support beam for the smoothing board and the cutter and with which these members can swing relative to the implement frame in a pendulous movement. Another pivotal mounting at least for the tool allows, in part, the tool to be raised and lowered relative to the ground between ground-working (operative) and rest (inoperative) positions, the latter of which may be used for higher-speed travel of the implement over the ground.
Ground-working implements for agricultural lands can have soil-loosening tools, preferably constituted as rotating members, e.g. tilling tines or cutters, which serve primarily to loosen surface zones, the smoothing board here serving to level the loosened soil and prepare it for sowing.
Should a swinging coupling be provided between the coupling beam and the holder in these rotary tilling devices, the implement can readily compensate the position of the device with respect to the ground by the pendulous movement of the support or coupling beam about the longitudinal axis thereof. This can also assist in adjusting the height of the implement with respect to the drawing vehicle, for example a tractor, because the coupling beam can be connected to the tractor so as to be swingable up and down relative thereto.
While such equipment is excellent for agricultural preparation it can, of course, also be used exclusively for ground leveling using the smoothing board or blade with the cutting tool or tools in their raised positions.
A conventional implement of the latter type, in which rotating tools are mounted so that the cutter can be swung upwardly on journals provided on the smoothing blade, makes use of a cylinder mounted on the holder and whose piston at its free end is pivotally connected to an articulation on the housing for the cutter. This arrangement can, therefore, without altering the position of the smoothing board or blade, allow the cutter to be swung upwardly into its inoperative position in which the cutter is withdrawn from contact with the ground.
The smoothing board, on the other hand, is swingably mounted on the holder and can be pivoted by a further piston/cylinder unit about its journal on the holder. The two journals provided on the smoothing board, namely the journal upon which the cutter unit is swingable and the journal by which the smoothing board is connected to the holder, are only spaced apart minimally. As a consequence, when the smoothing board is swung even through a relatively large angle between smoothing board and ground, there is only a comparatively small angular change of the position of the cutter. The control of the cutter and smoothing board is thus done separately by respective operator-controlled effectors. The earlier implement is relatively massive and bulky and, because of the aforedescribed control system, requires excessive attention on behalf of the operator for reliable operation.